Smoke producer



` March 2, 1937.

D. J. GRAYl ET AL 2,072,364

SMOKE PRODUCER vFiled Jan. '7, 1933 2 She'etS-Shet l L ma* /IHHHHHHHENNHNHHHHEHHHHHHEHHHHNHHNHH'N BHW j www' March 2, 1937. D. J. GRAY ET AL- SMOKE PRODUCER Filed Jan, '7, 1933 2 Sheets-Sheet 2 Patented Mar. 2, 1937 1 Nlri-:D STATES PATENT oFricE SMOKE PRODUCER Application January 7, 1933, Serial No. 650,686

3 Claims. (Cl. 126-595) This invention relates generally to smoke producing devices, and particularly to a type adapted to produce smoke from sawdust for use in meat packing plants.

5 The mainobject of this invention is the provision of a smoke producing apparatus which will produce a uniform and ample supply of smoke with a minimum amount of labor and discomfort on the part of the workmen.

The second object is the production of a smoke producing unit which can be moved-into position for service in a number of different locations.

The third object is to construct a smoke producerwith a regulating appliance for preventing same from producing an undesirable amount of heat, and at the same time producing a maximum amount of smoke. y

The fourth object is to entirely eliminate the necessity of placing a charge of sawdust on the iloor of the smoke producing room and continually raking same for the purpose of maintaining a smoldering condition.

The fth object is to construct the device ina manner that a pressure can be maintained in the sawdust above the retort of the device for the purpose of preventing same from bursting into flame.l

These, and other objects, will become more apparent from the specification following as illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical section through a representative form of smoke house showing the device in use.

Fig. 2 is a plan of the device.

in Fig. 2.

Fig. 4 is a section taken along the line 4-4 in Fig. 3. r

Fig. 5 is a plan of Fig. 4. Fig. 6 is a diagrammatic view of the damper regulator. l

Similar numbers of reference refer to similar parts throughout the several views.

`Referring in detail tothe drawings', same will 45 be seen to consist of an underfeed Stoker which, in this instance, is mounted on a vehicle I0 and is comprised of a storage hopper4 II for sawdust I2 which is fed therefrom through a sawdust-feed duct I3 by means ofa sawdust feed screw I4. 50 The duct I3 terminates in a retort I5 which is surrounded by a plenum chamber I6 to which air is delivered by means of a fan inthe casing Il through the air duct I8. Rotation is supplied to thel screw I4 and the fan by means of a 55 motor I9. Air is permitted'to pass from the plenum chamber I6 through the openings 26.

A floor. plate 2i surrounds the retort I5 near its top edge. Resting on the oor plate 2| is a drum 22 whose top side 23 is closed except for an 60 opening 24 over which is mounted a short stack Fig. 3 is a vertical section along the line 3 3 25 containing a damper 26. A smoke deectin cap 21 is placed above the top of the stack 25 in spaced relation thereto. The damper 26 is normally set in almost a fully closed position in order to maintain a pressure on the top side of the smoking sawdust 28.

In order that the sawdust 28 may burn with a deficiency of air there is provided a damper control which will still further close the damper 26 should the temperature within the drum 22 rise an objectionable amount. This consists simply of a helical bi-metallic element 29 which will be referred to as a thermostat and whose end 36 is disposed between-the contact screws 3l and 32; the former being joined by a wire 33 to 'a hinged arm 34 which is normally urged downward by means of a spring 35 and carries along its length an adjusting screw 36. The wire 31 connects the screw 32 with the hinged arm 38 which is urged downwardly by the spring 39 and carries an adjusting screw 46. f

On the shaft 4I of the damper 26 is a worm Awheel segment 42 provided with the inturned lugs 43 and 44, the former of which engages the screw 36 when the temperature in the drum 22 rises an objectionable amount, and the lug 44 engages the adjusting screw 46 when the temperature in the drum 22 falls below a desired amount.

The worm wheel 42 meshes with the worm 45 which is secured to the shaft 460i a reversible motor 4l, one of whose-leads 46 extends to the contact point 49 under the arm 34, while its,lead4 56 connects with the contact point 5I which engages the arm 38. A neutral wire 52 extends from the motor 4l through the source of power 53 to the thermostat 29.

It is desirable to provide an agitator 54 within the hopper I I for the purpose of preventing arching of the sawdust in the hopper. 'I'he type of agitator illustrated is shown in detail in Patent Number 1,812,911.

The operation of the device is as follows: A supply of' sawdust I2 is placed in the hopper II and the motor I9 is started, causing the sawdust to be carried by the screw i4 into the retort I5 where it is ignited in any convenient manner. The sawdust 23 is now permitted to burn within the drum 22, but with an insuicient amount of oxygen and under a pressure above that of the atmosphere, in order to prevent it from bursting into a blaze, the damper 26 having been set with relation to the shaft 4I by means of the set screw 55 to provide the desired amount of restriction in the stack 25 to secure the right smoking condition, during which time the thermostat end 30 iloats between the screws 3l and 32'.

If, due to atmospheric conditions, moisture containedy in the sawdust, or other factors, the re begins to die down the end 36 will come into contact with the screw 3l, causing current to flow from thesource 53 through the thermostat 29, the wire 33, the arm 34, then through the wire 48 to the motor 41 and back through the neutral wire 52 to the source 53, causing the motor 41 to turn the worm 45 in a direction which will cause the damper 26 to move toward a vertical position until the re is either built up to the desired point which will cause the end 30 to engage the screw 32, or, if the fire has gone out entirely, the motor 41 will` be stopped by reason of the fact that the lug 43 has lifted the arm 34 away from the contact 49. If, on the other hand, after the smoke producer has been operating satisfactorily for a period of time the temperature begins to rise, the damper 26 is made to closel by reason of the fact that the end 30 engages the contact 32 causing the motor 41 to turn in the opposite direction, due to a fiow of current through the end 30 until the temperature within the drum 22 either drops suiiiciently for the arm 38 to leave the contact 32v or the lug 44 has lifted the arm 38 out of engagement with the contact 5I.

In other words, the arms 34 and 38 are tripped when the damper 25 is wide open or fully closed, although in normal operation the damper 25 would float between these two extremes under the control of the thermostat 28.

It will be-seen from the foregoing that we have evolved a new apparatus for producing smoke from sawdust, involving not only the elimination of secondary air but the confinement of the smoke produced under pressure for the purpose of preventing the smoldering sawdust from bursting into ame.

It will be understood, of course, that this can be accomplished by providing an insufficient quantity of primary air, in which event however, only a 'limited amount of smoke can be produced; but by supplying a desired amount of primary air to produce the necessary amount of smoke and then holding this smoke under pressure there is no danger of the gases bursting into flame, sincev there is an insuflicient proportion of oxygen present to support this degree of combustion.

Owing to the fact that the drum 22 is filled with smoke under pressure when the device is in operation the thermostat control for the pressure element can be substituted by or supplemented by one or both of two equivalent control systems. For example, instead of employing temperature to actuate the control, a pressure actuated device would serve equally well, or there could be employed a photoelectric cell by means of which any light occasioned by a burning of the gases in the drum 22 would, through the cell, cause the control apparatus to be operated.

The use of pressure controlled devices and photoelectric cells are so well understood as to require no eyplanation in regard to the manner in which they would be employed.

It is of course understood that the fan I1 is provided with a control for its inlet whereby the amount of airdelivered to the combustion may be accurately controlled, and thereby the thermostatic control in conjunction with the fan control, becomes a positive means for regulating the amount of smoke produced by the device.

It will be understood, of course, that the damper 26 constitutes a means for controlling the air delivered by the fan when pressures are employed in the drum 22; but when the photoelectric cell,

for example, is employed it will in most cases be found necessary. to further regulate the flow of air by means of the damper on the fan itself.

Whereas the Stoker has been shown mounted on a four wheeled truck, in many instances it will be found desirable to leave the entire stoker outside of the smoke housefusing a duct from the smoke chamber leading into several smoke houses, in which event the smoke delivered to each house would be controlled by means of dampers and one machine could do the work of several, and at the same time the machine would always be accessible for feeding and servicing.

It is also desirable in some installations toprovide an agitator for the smoldering sawdust, and this may either be manually or power driven as desired, although in most instances when the automatic damper arrangement is employed the use of an agitator will be found to be entirely unnecessary.

We claim:

1. In a. smoke producer, the combination of a vehicle, a sawdust hopper mounted on said vehicle, a retort including a plenum chamber also mounted on said vehicle, a conveyor worm within a sawdust feed duct communicating between said hopper and retort, a fan for supplying air to said plenum chamber, means for driving said worm and fan, a pressure-tight drum mounted over said retort within which said sawdust may be burned, a smoke outlet at the upperv end of said retort having a deflector on the top side thereof and having a damper within said outlet together with an automatic control for said damper including a reversible motor for actuating same in a manner to move said damper in a closing direction during over-temperatures and to move said damper in an opening direction during under-temperatures, and trip means associated with said damper whereby said motor will be stopped in either of its extreme positions.

2. A smoke producer having in combination an underfeed sawdust delivering stoker including a retort in which the delivered sawdust is held, means for feeding air and sawdust into said retort from its under side, a closed drum forming an insuflicient combustion space communicating with said retort, means for restricting the flow of smoke from said drum for the purpose of reducing the tendency for the sawdust to form a blaze and a temperature controlled outlet for the said drum adapted to restrict the escape of smoke therefrom when the temperature of said drum exceeds a predetermined maximum.

3. A smoke producer having in combination a fuel feed duct, a worm for moving sawdust through said duct upwardly into said retort, a fan for supplying air upwardly through said sawdust, a drum communicating with said retort having insuicient combustion space for the complete burning of the sawdust, said retort having a. smoke outlet opening, a damper for restricting the flow of smoke from said opening and temperature controlled means for moving vsaid damper to in crease the restriction to the flow of air through said opening during over temperatures in said drum and to decrease said restriction during subnormal temperatures in said drum.

ALFRED B. MEEG.V DANIEL J. GRAY. 

